In the Final Crisis: Legion of Three Worlds comic book series, the Legion reaches out for help against a powerful foe they can't beat alone. From the moment Superman landed on Earth until the end of time, the Time Trapper has sought to erase Superman's impact on the universe. But the Legion of Super-Heroes have always been there to stop the relentless villain. Now, one Legion isn't enough as the Time Trapper taps a twisted mirror image of The Boy of Steel from a parallel Earth long dead: Superboy-Prime.